


The Boy At King's Cross

by Sicarian_Marionette



Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: M/M, Potterlock
Language: English
Status: Completed
Published: 2012-12-07
Updated: 2012-12-07
Packaged: 2017-11-20 14:08:49
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,594
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/586206
Author URL: https://archiveofourown.org/users/Sicarian_Marionette/pseuds/Sicarian_Marionette
Summary: <blockquote class="userstuff">
              <p>John was feeling a bit silly, being an 11 year old with a couple of giant trunks on a trolley with all these strange books and bits and bobs inside. He reached the middle of platforms 9 and 10, and had absolutely no idea what to do next. Good thing his parents decided to bring him there a bit early.</p>
            </blockquote>





	The Boy At King's Cross

**Author's Note:**

> Written for johnlockchallenges' Gift Exchange! Prompt by nhanhacoisoetalbanana. I'm sorry this is really late, and isn't exactly what you wanted! :( Your prompt was wonderful, by the way.

1st Year

August felt new to John. Normally, he’d be with his mum and Harry buying his books and school supplies at the nearest shopping centre, but apparently, John wasn’t normal. On John’s 11th birthday 5 months ago, he was visited by an old man wearing midnight blue robes, with a matching pointy hat (what was his name? Dubblemore? Donmudor?). John was a wizard. Muggle-born, but a wizard nonetheless.  


The rest of the months went by quickly, and instead of the shopping centre, buying pens and books and reams of paper, John Watson found himself shopping for his school things in Diagon Alley.  


He and his parents could not believe their eyes as they watched wizards and witches rushing about, parcels and books either being carried or floating about, displays and posters changing appearance at the blink of an eye. He felt the warm glow inside him as he grasped the wand from Olivander’s (9 inches, juniper with a phoenix tail core, oiled with a mix of powdered dragon bone and extract of asphodel, excellent for charms and potion-making). He gaped at the mountains of magical texts as he bought his books from Flourish and Blotts. He peered at the shelves of potions ingredients at the Apothecary. He begged his parents to let him have an owl (they didn’t get him one, much to his dismay). He tasted butterbeer flavoured ice cream from Florean Fortescue’s (it was new, and tasted delightful. No wonder it was such a bestseller).  


John spent the rest of the month poring over the textbooks and practicing spells with his new wand. Before he knew it, September 1st had come around.  


His parents dropped him off at King’s Cross station at 9:15 am, since they still needed to bring Harry to her school. He walked around, wondering where platform 9 ¾ was. John was feeling a bit silly, being an 11 year old with a couple of giant trunks on a trolley with all these strange books and bits and bobs inside. He reached the middle of platforms 9 and 10, and had absolutely no idea what to do next. Good thing his parents decided to bring him there a bit early.  


“You walk through that wall over there.”  


John looked around to see who managed to answer the question he didn’t even voice out. What he saw was a boy who looked around 6 or 7, wearing a public school uniform, black curls framing an angular face still graced with baby fat, pointing at the wall separating the two platforms.  


Before John could ask questions, the boy began speaking. “You’re a Muggle-born aren’t you? It’s your first year to go to Hogwarts, and you have a little sister. You’re close, and she doesn’t want you to go away. Oh, and nice to meet you, John H. Watson. ”  


He blinked, surprised. “Yeah, that’s about right,” John remarked, impressed. “How’d you know all that?”  


The boy shrugged. “You have two trunks on your trolley. That’s a giveaway. One’s for your clothes and the other’s for your school things. You’re lost. You keep looking from platform 9 to platform 10, and you aren’t looking at any ticket, meaning you’re scared to take it out because you might lose it or others might see. As for your little sister, your trousers are all wrinkled on one leg, like someone hugged it too tight. And you smell slightly of baby cologne, something little girls typically wear.”  


“And my name?” John asked.  


“Easy.” The boy smirked. “It’s on an enormous sticker on your trunk.”  


“That’s…amazing!” exclaimed John, impressed.  


The boy raised his eyebrows, his grey eyes brightening. “Interesting. That’s not what people usually say?”  


“What do they usually say?”  


“’Mind your own bloody business, boy.’” He said with a grin.  


John laughed, extending his hand. “John H. Watson, but you already know that.”  


“Sherlock Holmes.” He said as they shook.  


“So you’re telling me I should walk through that wall then?” John asked his newfound acquaintance.  


Sherlock nodded. “Any wall between platforms 9 and 10, actually. Come on,” he added as he tilted his head towards the wall.  


John took a deep breath. Could he trust this kid? He could end up crashing into the wall. Better that than not trying though. God forbid he be the first kid to miss the train because he was too chicken to walk through a barrier.  


With that thought he swallowed, tightening his grip on the trolley.  


“You could run if you’re scared,” piped up Sherlock with a smirk on his face.  


“I’m not scared!” John denied.  


Sherlock shrugged. That seemed to be his favorite gesture.  


He started off with a slow walk, gathering speed. As he neared the foreboding column of solid brick, he grit his teeth, closed his eyes and broke into a run.  


He expected to hear a loud thud before the handle punched his stomach. What he didn’t expect was the sound of a train whistle, the hooting of owls. He didn’t expect the smell of smoke and morning air, mixed with the occasional whiff of perfume.  


John opened his eyes, and found himself staring at a black engine, clearly labeled “Hogwarts Express”. A glance at the wall he just passed through told him he was at platform 9 ¾. He looked around, and accepted that he was at the right place when he saw most of the people in robes, not unlike the ones the old man wore at his birthday (Dunderbore?).  


“You might as well get on the train. It’ll leave soon.”  


John whirled around to see Sherlock sitting on a bench by the wall.  


“How about you?” asked John.  


With a customary shrug, Sherlock replied, “My brother goes to Hogwarts. He’s in his 4th year. I have to wait for three more before I get on that train. I don’t see why Professor Dumbledore won’t let me enroll early.”  


(Dumbledore! There we go!) “Maybe he thinks you aren’t ready? I mean, you’re pretty brilliant from that observing thing you did to me, but oh well. I’ll see you soon, then?”  


“Not soon,” said Sherlock. “But you’ll probably see me next year.”  


After a brief frown, John conceded. “Next year then.”  


With one last handshake, John boarded the train.

****

2nd Year

“You aren’t still lost are you?”  


John grinned as he took his cup of hot cocoa from the counter. He looked around to see Sherlock, in a different uniform this time (still public school though. The kid’s parents must be really rich.)  


“You’re in Gryffindor aren’t you?”  


He wasn’t even wearing his robes. “Yeah, how’d you know?”  


“Muggle-borns don’t get into Slytherin, you’re clever, but not clever enough for Ravenclaw. That leaves Hufflepuff and Gryffindor, but you aren’t boring. Gryffindor it is then.”  


John grinned. “You know the way you do it is still awesome, and I go to a school for wizards.”  


Sherlock shrugged it off with a small smile. “It was a deduction based on what I observed. And I did have a year to think about it every now and then.”  


“Well it’s still awesome. You’re attending a different school now?” asked John, as they headed for the platform.  


Sherlock nodded.  


“My old school didn’t want me back, as usual,” he explained, his green eyes twinkling in amusement (hey, weren’t they grey last year…?) “Apparently I ‘engage in behavior not proper for my age, terrifying my class, schoolmates and school staff.”  


“What behavior exactly? And are you saying you get kicked out every year?” John wondered. “You didn’t run around naked on the last day of classes, do you?”  


Sherlock stopped, appalled. “Why would I do such a thing? And why is the first reason you thought of?”  


John laughed. “Someone did it last June. The last day of school and the first thing you see at breakfast is someone else’s privates. Hogwarts is really something else.”  


“If that’s how it is every day there, I might as well go to Durmstrang.” Retorted Sherlock as they walked on.  


“Durmstrang?” asked John. “You mean there are other wizarding schools?”  


Sherlock nodded. “Mycroft would have gone to Durmstrang, but mother convinced him otherwise.”  


“Your brother huh…” John trailed off to an awkward silence.  


“I dissected a dead cat.”  


John started. “How old are you again?”  


“Eight.” Said Sherlock with a smirk. “I found one at the playground and began poking around its insides. I used my scissors and cut out its heart and showed it around.”  


They arrived at the platform. (No, John didn’t need to run anymore.)  


“Hey, why do you attend a Muggle school anyway? Isn’t your whole family magic? What do they call those again….”  


“Pure-bloods,” Sherlock supplied. “My mother wants us to know about Muggles. Most wizards are complete idiots when it comes to acting without magic. Clueless about telephones and mail and television. She doesn’t want us to become that way.”  


“Sounds logical.” Agreed John.  


The whistle of the Hogwarts Express blew twice. It was time for John to board.  


“Goodbye then, I guess.” Sherlock extended a hand.  


“I’ll be looking forward to the day you get on the train with me, Sherlock Holmes.”  


Sherlock gave a small smile.  


With a handshake, John boarded the train.

****

3rd Year 

“What is the exact nature of your relationship with Sherlock Holmes?”  


John looked up from his tuna sandwich to see a stocky man wearing Slytherin robes standing in front of him. His dark brown hair was slicked back, and his eyes were an odd sort of grey. A shiny Prefect’s badge winked from his chest.  


Clearing his throat of the traces of sandwich, John answered, “I don’t see how that’s any of your business.”  


“Oh believe me, Mr. Watson. It is,” said the man. His voice seemed to imply a threat, but John couldn’t see one (except perhaps that umbrella).  
John stood up slowly, his eyes narrowing and left hand straying to his wand pocket. “It really couldn’t.”  


The Slytherin smiled. “You wouldn’t want detention before your first day, John.”  


John didn’t move.  


With a sigh, the man unrolled a scroll of parchment from his pocket.  


“2 years ago, you met Sherlock Holmes at King’s Cross Station. He showed you how to get through the barrier to platform 9 ¾. Why? Sherlock Holmes does not simply help strangers. You spoke for a minimum of 5 minutes, maximum of 10. Nothing extraordinary. People have meaningless conversations all the time.  


“1 year ago, you met once more, this time at the café near the station entrance. Instead of the typical behavior wherein you would simply acknowledge each other and leave for your own specific business, you walked to the platform together. Before parting, you said ‘I shall be looking forward to the day you get on the train with me, Sherlock Holmes.’”  


John blinked. How’d this stranger know all of that?  


“You might call me a concerned party, and it is in your best interests that you cease your contact with Sherlock Holmes immediately.  


“John Watson,” said the man, turning away. “It’s better for you know about this now. Sherlock Holmes will not be joining you on the Hogwarts Express next year. Good luck.”  


As if on cue, a group of girls walked past, covering John’s view. He sat back down, contemplating on the Slytherin’s words.  


“You’re early. You’re usually at the station at this time.”  


John gave a small smile. “You wouldn’t happen to know the Slytherin Prefect, would you?”  


Sherlock sat down beside him. “Oh. Mycroft. Did he pay you money to spy on me?”  


“Your own brother? He does that?” John was surprised.  


“He pays Muggles to spy on me and send him mail. How he receives them at Hogwarts I’ve yet to find out,” Sherlock shrugged.  


The whistle blew twice. John stood up and readied his things.  


John extended a hand. “Am I seeing you on the train next year?”  


Sherlock smiled. “Maybe.”  


With a handshake, John boarded the train.  


Alone at his compartment, John thought about that maybe as he watched the city speed away. Why a maybe?  


The door rolled open. Through the reflection on the window, John could see it was Mycroft.  


“You’re Sherlock’s brother.” John wasn’t so scared anymore. Something still felt off, but he ignored it.  


“And you ignored what I just told you.”  


“Why do you treat him that way? You spy on your own brother all the way from Hogwarts. Can’t you just ask him what’s going on?”  


Mycroft sighed, watching the countryside come into view. “I do not have the best of relationships with my brother. Contrary to his belief, and perhaps yours as well, I simply wish the best for him.”  


John snorted. “Well you do a bloody brilliant way of showing it.”  


As he stepped out of the compartment, Mycroft said, “I have my methods.”  


John was silent the whole journey. 

****

4th Year

John was running late. It was already quarter to 10 and he wasn’t even at the platform yet. The bulk of the trunks wasn’t much help either.  
It was a bit of a run, but with luck (and perhaps some very annoyed Muggles), John found himself sitting across Mike Stamford (Hufflepuff, not too bright, but not too shabby either. A great help at Herbology), panting as the train began to gather speed.  


“All right then, John?” Mike asked cheerfully.  


Still tired from the run, John simply nodded.  


Where’s Sherlock? Maybe at another compartment.  


“Hey, Mike. I’ll walk around for a bit. Need to see a man about a do- I mean, er, an owl.”  


Mike looked confused. “You have an owl?”  


“No, I- Christ. Could you stay here a bit?” John didn’t have too much patience for this now.  


“Sure.”  


His compartment was near the front of the train, so he slowly made his way down the express, looking through each compartment in the hopes of seeing a familiar boy with strange eyes and dark curly hair. It took him a while to go through the entire train. The Hogwarts Express couldn’t very well carry most of the students if it were a tiny engine.  


He saw some interesting things along the way. First years were busy gaping out the window or trying spells on each other. A number of students were asleep. Quite a few were snogging (John shuddered. Sure he was 14, but there was something about public displays of affection that made him uncomfortable).  


“I did tell you he wasn’t getting on the train.” John sighed. Mycroft.  


“You don’t need to. I remember every time you pass me by.”  


Mycroft, this time with a shinier Head Boy badge, was sitting across a Ravenclaw girl (Head girl), who seemed to be engrossed in taking down notes.  


“I’m surprised you still haven’t figured it out, given that I’ve passed you several times across numerous corridors, and the fact that you’ve had a whole year to think on it.”  


John turned to face the Slytherin. “You could always tell me where he is.”  


With a sigh, Mycroft moved to close the compartment door. “Not on this train, John.”

****

5th Year

John wasn’t late this time. His trunk was sitting at a compartment, with a handy little charm to prevent others from shoving it out and claiming the seats. He was sitting at the benches on the platform, fiddling with the Quidditch Captain’s badge in his pocket, just watching the crowd of students begin to form. He wondered when Sherlock would get there.  


The whistle blew twice. John looked around to see of he popped up at all.  


With a shrug, he boarded the train.

****

6th Year

John walked straight into the train and took a compartment.  


When the whistle blew twice, he made no move to check outside if a dark-haired boy was anywhere.

****

7th Year

With his girlfriend latched onto his arm, John didn’t notice the dark haired teenager in unassuming Muggle clothing standing off to the side of the platform. He did feel that something was familiar, but was too busy to give it any notice.

****

Years later…  


Gregory Lestrade, D.I., burst into one 221B Baker street, and the sight wasn’t exactly the best of things to see first thing in the morning. The words at his mouth died immediately. In front of him was a half naked Sherlock Holmes, closing in on a John with a half-on dressing gown. He couldn’t see John’s face from the door, but the consulting detective’s eyes looked particularly hungry. Sherlock was about to, well, descend, on the doctor, when Lestrade felt the need to interrupt.  


“…In 3 minutes I'm going to walk in, and you boys are going to be, erm, decent,” he said as he closed the door, trying to forget the image.  


Later on, when everyone had considerably more clothing on, Sherlock grumbled, “This better not be less than an eight.”  


From the kitchen, John added, “I’d have to agree with him on this one, Greg.”  


Lestrade cleared his throat, turning slightly pink. You’d probably agree with him on anything as long as he has his-  


“Gregory.”  


A crisp voice cut through the flat. Mycroft was at the door, signature umbrella in hand, with a manila envelope on the other. He stepped into the flat, gave it a once over and made his way through the mess to sit at the couch.  


Casually, he drew a wand from his pocket, and waved the doors and curtains shut. He cast a Muffliato spell at the walls and a Muggle-repelling charm at the door.  


John’s eyes were wide, his shoulders stiff. It had been years since he cast his last spell (a wandless charm to seal the floorboard underneath his bed), and ages since he last saw another with a wand. Lestrade was pale, like he still couldn’t believe that magic was real, but kept quiet. Sherlock scoffed.  


“Don’t show off, Mycroft. Don’t you have a rule about magic and Muggles?”  


Mycroft smiled. “Singular, brother dear. John Watson is very familiar with the world of witchcraft and wizardry. Don't you remember your little friend at King's Cross?”  


Sherlock’s eyes narrowed at his brother. “John isn’t a Squib. He would have recognized you.”  


Sighing, John turned to Sherlock. Might as well let that cat out of the bag. “I’m not a Squib, Sherlock. I’ve been.. out of touch."  


Sherlock's tight expression slowly melted away. “You’re a wizard,” he said softly.   


“Well done Mycroft, you finally got someone competent enough to spy on me. That enough for you, oh minor British government official? Or should I call you Minister of Magic?”  


“You’re the Minister of Magic?” asked John incredulously. He had been out of touch for the longest time.  


Mycroft coughed. “Sherlock, John is not spying on you. And after the whole Voldemort phenomenon, they needed a Minister who could stand appearing as a common Muggle in public. That narrowed down the candidates considerably.”  


“He was the only one in that list in the first place,” whispered Sherlock to John.  


Greg Lestrade only understood half of that conversation, and feeling left out said, “Could we focus on the case here?”  


Mycroft placed the manila envelope on the table, gesturing the two flatmates to take a look. Lestrade began to explain.  


**** 

John closed the front door and turned to Sherlock.  


“We could, erm, continue?” he suggested awkwardly.  


Sherlock just stared. “You’re a wizard. Why couldn’t I feel your magic?”  


John sighed. “My uncle died in the army while I was at Hogwarts. I swore to head over to the battlefield as soon as I graduated, maybe help out as a doctor.”  


“You couldn’t help out as a wizard, so you went to St. Bart’s.”  


Nodding, John added, “I went to St. Mungo’s first. So I could get the medical degree, but I needed a lot of recommendations before St. Bart’s took me in for my fellowship. I couldn’t use magic in Afghanistan. Not even while healing, so I just.. stopped. I was born a Muggle, Sherlock. It wasn’t so hard for me to step away from it.”  


“And you couldn’t tell me anything because of the Statute of Secrecy.”  


“You couldn’t tell me anything about it either.”  


Sherlock sighed. “I’m a Squib, John. It happens every three generations, always to the second born. Strange, but what is the wizarding world but strange? What did Mycroft say about your friend at King’s Cross?”  


“Hm? Oh, there was this kid at King’s Cross station. Showed me the way to the platform. I forgot his name though, it’s been ages….” John trailed off. Then something clicked.  


“YOU!” he exclaimed, his head reeling. “No wonder something felt familiar when you deduced me. You’re that boy I kept talking to at King’s Cross!  


“You told me I was a 1st year Muggleborn with a clingy little sister. And you were what, 7? 8? You told me you went to a Muggle school because your mother didn’t want you to become ignorant.”  


“Partly true. I’m a Squib. I needed some way to survive without family.”  


“….so that’s why you kept telling me ‘maybe’ when I would say I looked forward to seeing you on that train.”  


Sherlock nodded.  


“You could have told me.”  


“I was young. I was still ashamed I wasn’t magical.” Sherlock shrugged.  


“You used to do that a lot,” remembered John. “I guess some things never get old for you.”  


“I’m getting bored of this conversation.” Sherlock announced. “I’m taking you up on your earlier offer.”  


John was slightly lost. A topic change that quick was a bit disorienting. “Which is..”  


Sherlock grinned. “Continue where we left off.”  


“Excellent.”

**Author's Note:**

> It's been about a year since I've posted this fanfic and I'm only staring to go over it again now. I realized that the ending seems rushed (it was), and that I totally missed an opportunity to elaborate on Mycroft as the Minister of Magic, the case, Lestrades involvement, etc. (I have the details planned out for this, but I was rushing.) I don't know when I'll be updating/editing, but I will be. 
> 
> Prompt given was "Sherlock is a Squib." nhanhacoisoetalbanana wanted them to discover the magic when they were at 221B, and I don't think I put that in there very well so I'm really sorry :(


End file.
